Ministry of Defence: CHOtS secure communication system

One of the biggest accredited systems

at SECRET level

Fujitsu designed, built, implemented and managed Corporate Head Office technology System (CHOtS) for the Ministry of Defence (MOD).
The system supported 25,000 civilian and forces personnel and allowed an additional 70,000 MOD staff to communicate securely via its network. Access to information was domain-based, with links to MOD messaging systems. It was operational at 24 HQ locations and more than 200 subsidiaries in the UK, Europe and the USA.
In 1991, the Ministry of Defence (MOD) decided to embrace email and office automation, following a CSA report in 1986 and decisions made in 1987. Properly employed, they knew these innovations would reduce costs and improve communications around the world.
But what about security? Was this an opportunity to converge and standardise the MOD's vast IT estate? And could it be done without locking in to expensive bespoke coding and support?